Whether the adjustment of the active bevel gear and the driven bevel gear is correct or not, it plays a decisive role in the service life and running stability of the main reducer. After the assembly and assembly of the main reducer and differential, especially after the replacement of some parts, the suitable adjusting gasket must be selected through accurate measurement and calculation; the gasket is changed by changing the gasket. The driving gear on the output shaft of the transmission is moved axially to make the meshing mark at the best position; by changing the thickness of the gasket, the driven gear is moved axially, so that the meshing gap is in the prescribed tolerance range. The driving bevel gear and the driven bevel gear can only be replaced together. Before removing the transmission, it is better to measure the average clearance and deviation of the tooth surface. As long as repairs affect parts of the active bevel gear and the driven bevel gear, the thickness of the adjusting shim must be re measured. As long as the bearing seat, the rear bearing of the active bevel gear, the outer seat ring of the needle bearing of the one gear and the rear axle of the output shaft are replaced, the active bevel gear must be adjusted by adjusting the thickness of the gasket to make the meshing mark of the main and driven bevel gear in the best position. The specific methods are as follows: the check of the meshing condition of the main and driven bevel gears is to observe the location of the teeth engaging traces and use them as the basis for adjustment. The process is as follows: first, the tooth surface is cleaned, and the medium - paid oil pigment (such as Hong Dan) is evenly coated on the tooth surface of the active (or driven) gear, and the active gear is rotated back and forth, and the load is made a little. Then the contact marks on the tooth surface can be examined, and the normal engagement can be judged. If the meshing situation is not normal, the position of the active gear and the driven gear should be repeatedly adjusted to make the contact marks on the tooth surface of the driven bevel gear reach the 2/3 of the length of the tooth, the small end of the mark edge 2~4 mm, and the edge of the mark to the edge of the tooth surface 0.8 to 1.6 mm. The meshing area between the main and the driven bevel gears is adjusted by the axial displacement of the main and subordinate bevel gears. The axial displacement of the active bevel gear can be adjusted by the increase or decrease of a number of different thickness of the gasket. The clearance of the tooth side is usually 0.15 to 0.40 mm. The axial displacement of driven bevel gear can be adjusted by adjusting the ring of the rotary differential bearing. The number of one end increases, and the other side decreases correspondingly, keeping the bearing pretightness unchanged. When the active bevel gear, the driven bevel gear assembly, the gearbox shell, the main reducer cover, the differential cover shell or the bearing are replaced, the driven bevel gear must be adjusted. The adjustment of the driven bevel gear includes the adjustment of the bearing pre tightness of the driven bevel gear (differential) and the adjustment of the meshing gap between the main and the driven bevel gear. (1) adjustment of the pre tightness of the driven bevel gear bearing when the bevel gear works, because the transmission moment will produce an axial force, and this force acts on the bearing through the gear. If the bearing has no pre tightening force, the axial displacement will occur under the action of this force, which not only changes the position of the gear meshing, but also makes the gear tooth change. There is a large gap in the front bearing of the wheel axle. In addition, under the action of torque, the shaft will be skewed and swaying, which will cause the gear to mesh properly, and make the wear more serious. After the bearing is preloaded, a part of the axial load is balanced by the gear shaft, which reduces the axial displacement, that is, the axial stiffness is increased. When the bearing is preloaded, the pretightening force should not be too large. Too large will cause heat when the load goes through the ambassador bearing and reduce the service life of the bearing. Therefore, the inspection should be adjusted according to the requirements of the manufacturer. The adjustment of the pre tightness of the driven bevel gear bearing is also called the adjustment of the total thickness of the adjusting washer of the driven bevel gear, so that the driven bevel gear (differential) is rotated by the adjustment of the gasket, and the axial gap is pushed in the axial direction. The concrete steps are as follows: remove the cover of the main reducer. Remove the outer race of the sealing ring and differential bearing and take out the adjusting shim. The outer race of the bearing is mounted on the transmission housing, and the standard (model) gasket with a thickness of 1.2 mm is installed at the same time. Note: the outer race of the bearing should be loaded into the block. Install the outer race of the outer bearing on the main reducer cover without adjusting the shim. The differential gear with speed odometer driving gear is mounted on the transmission housing, and the bolt is tightened with the torque of 25 N m. Do not turn the differential when measuring, because it may affect the measured value. (2) check the meshing clearance of the meshing gap between the main and the driven bevel gear: when the clearance of the bearing is adjusted and the meshing position of the gear is adjusted correctly, if the clearance exceeds 0.8 mm (the use limit is 1 mm), the gear should be replaced. It is not allowed to reduce the backlash by changing the relative position of gears and ignoring the correct meshing of gears. When measuring the backlash, the dial indicator bar is perpendicular to the large tooth surface of the driven tooth, and the active gear shaft is fixed, and the driven gear is driven. The reading of the dial indicator is the backlash value. The gauge can also be measured by inserting a tape into the two gear. Measurements should be taken in several directions, and the difference in the clearance of each direction should not exceed 0.15 mm. After adjusting the axial clearance of the main and driven bevel gear bearings, the meshing clearance of the gear should be adjusted again. The meshing gap between the main and the driven bevel gear, the new gear is 0.10 ~ 0.35 mm, the allowable value is 0.70 mm, the use limit is 1 mm, if the standard is exceeded, the adjustment can be properly adjusted in the case of ensuring normal meshing. Adjust the engagement gap between the main and driven bevel gears, and adjust the position of the driven and driven bevel gears. If the number of adjustment gaskets (the position of the active bevel gear) is installed between the reducer shell and the active bevel gear bearing seat, or the two bearing cover of the driven bevel gear is removed, the cushion cover is moved to the other side to adjust the position of the driven bevel gear, but the total number of adjusting gaskets must be kept. And thickness unchanged, so as not to damage the clearance of the adjusted driven gear bearing.